


I Think Knot?

by hornycadetkeith



Series: TransSheith Week 2020 [2]
Category: Voltron: Legendary Defender
Genre: Breeding Kink, But no babies, Established Relationship, Face-Fucking, Frottage, Knotting, M/M, Married Sheith, Oral Sex, Plot What Plot/Porn Without Plot, Squirting, Trans Keith (Voltron), Trans Shiro (Voltron), mention of Keith/random blades, mention of past Shiro/Ulaz, s8 doesn't exist, trans author
Language: English
Status: Completed
Published: 2020-03-17
Updated: 2020-03-17
Packaged: 2021-03-01 04:21:41
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,569
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23179144
Author URL: https://archiveofourown.org/users/hornycadetkeith/pseuds/hornycadetkeith
Summary: TransSheith Week Day 2: Transitioning / Baby FeverKeith discovers that going on testosterone has some interesting side effects on his Galran heritage...
Relationships: Keith/Shiro (Voltron)
Series: TransSheith Week 2020 [2]
Series URL: https://archiveofourown.org/series/1665055
Comments: 5
Kudos: 104





	I Think Knot?

**Author's Note:**

> Terms used for both trans characters: cunt, pussy, cock, dick, clit dick
> 
> Also I apologize for the dumb names lol

Things had calmed down on earth since the fight with Sendak. Keith had taken the longest to recover in the hospital, but things were now pretty much back to normal. After Keith woke up in the hospital, Shiro was there almost every day, every moment he could. 

Shiro had been misty-eyed the first time Keith woke up to him there. Keith welcomed him to a hug and Shiro dug his face into Keith’s neck and since, then things between them had changed. For the much, much better. There hadn’t really been an official “we’re dating now” moment, but like the war, they just had a new normal now.

So despite how rough things were still in the aftermath, Keith was the happiest he could remember being. The only downside was going away for months on Blade missions and missing Shiro _achingly._ But they communicated when they could, and the reunion sex was always mindblowing.

Keith was on one of these missions right now, finishing up their efforts for a ship full of refugees that had become stranded on a hostile planet, needing first aid and supplies. It had taken months and Keith was more than eager to return to Earth and to Shiro. 

It was on the return trip that Keith noticed it. He’d been so busy the past few months he’d barely had a moment to himself. But now all he was thinking about was seeing Shiro again and he was getting _very_ distracted with himself. He’d just been laying back on his cot, hand shoved down his boxers and stroking his swollen dick when he felt a weird bump around the base of it.

It felt… weird to touch, it didn’t hurt, but it was strange, and unlike anything he’d experienced before. Sitting up in his bed, Keith threw the sheets off and pulled his boxers down, bringing his pad over to light up his bits.

The angle was weird, but he could see it. It wasn’t a bump, but a swell at the base of his clit dick. He pinched it again and it didn’t hurt or feel _wrong,_ like an ingrown hair or something. It felt like pinching the head of his dick, only it was more firm under the skin. If he didn’t know better… it almost looked like…

Keith knew about knots. He lived in close quarters with many galra males, he knew most of them had knots. He’d seen a few, touched a few. It was a really prevalent gene, so even half-galra or quarter-galra would be endowed with knots. But he’d never heard of people with clits having knots. 

A thought came to him. Keith came out as trans to his mom on the space whale and explained exactly what that meant. She’d been very chill and good about it, but she was really intrigued when Keith explained HRT and testosterone to her. Maybe this was why. Maybe there were side effects of HRT that he hadn’t been able to research at the Garrison because there was no information on additional side effects if you’re _half alien._ That not only was his body transitioning to human male, but to galra male as well. And all that entailed.

Which apparently meant a knot on his dick. 

More than ever, Keith couldn’t wait to get home to Shiro.

\------------------

Like usual, when Keith returned to Earth, there was a big dinner with _everyone_ there. You’d think they’d only got together once every few years with how big a feast was always planned. Normally Keith appreciated it, but today all he wanted was to get Shiro alone. 

It took a few courtesy hours, but they were finally able to slip away before the booze started flowing too freely. They’d both had a couple glasses of wine and were getting touchy enough that everyone waved them away when they left the mess hall with smiles and giggles. _Giggles._ Keith giggled now. With Shiro.

They barely fell on to Shiro’s large, admiral-sized bed and Shiro was all over him tearing off his dress Blade clothes, mouth attaching to any new patch of exposed skin. Keith was ready to just lay back and let Shiro lavish attention on him when, through his wine-drunk haze, he remembered.

“Wait- wait I have to show you something.” Shiro pouted as Keith pushed him up. Keith lifted his hips and pulled the rest of his Blade suit off, trying to ignore Shiro’s big, warm hands petting down his back and distracting him. 

“No, stop it, I’m trying to show you something.” His voice was more petulant than serious, but Shiro listened, whining as he flopped back on the bed and rested his head on a hand, staring at Keith expectantly. “So I think T is doing something new to me, something I didn’t even think about, I noticed it on the way home-”

“Are you okay?” Shiro sat up, looking more concerned now. Keith smiled and kissed his lips, “No, I’m fine, it’s… it’s a good change, I think. At least I like it.” He was starting to feel shy, hoping _dearly_ Shiro wouldn’t be weirded out by this change.

Keith laid back and spread his legs, keeping his eyes on Shiro’s as he parted his wet folds to expose his hard dick. He’d been on T for years and his dick had grown thick and long in that time, long enough to prick up when he got hard. Long enough for it to have a base for a knot to form. 

His quick dallying on the ship home made him realize the knot only formed when he was pent up or really horny. He was both right now, so it was swollen and noticeable. Shiro’s eyes were transfixed.

Keith stroked his thumb and forefinger up and down his stubby dick, rubbing around the knot when he reached it. The strange sensation, he found, would grow to be _quite_ pleasurable the more pressure he applied to it. It was for breeding and keeping seed _in,_ after all.

“Is that… is that a knot?” Shiro’s voice cracked and Keith chuckled, he hadn’t heard Shiro’s voice crack like that in _years._ Keith smirked and nodded, tongue poking out between his teeth. Shiro leaned forward and laid between Keith’s parted legs, eyes almost crossing he was staring at Keith’s dick so hard.

“So you know about knots then?” Keith couldn’t help feel powerful, with Shiro looking so blown away between his legs staring at his cock. Shiro’s face reddened and he nodded, “Yeah, uhm… Ulaz had one… it was a lot to take in.” 

Keith burst out laughing and Shiro sputtered, finally looking away from Keith’s dick to look up at him, “The IDEA of it was a lot to take in, oh my god! I’d just been freed from space prison and a hot alien was showing me his dick and- stop laughing!” Keith covered Shiro’s face with his hands and Shiro, the mature admiral he was, licked his hands. “Fine, yes it was a lot to take in my pussy too, it was very large, his dick was very big okay? That what you wanna hear, Mr. Look At My Knot?”

Keith’s gut hurt, he was laughing so much. He’d bent over Shiro’s head and was trying to catch his breath in between cackles. “And here I was trying to be vulnerable and show you this new part of me…” Keith leaned back and feigned indignance. Shiro just snorted and kissed the inside of his thigh, putting his focus back on Keith’s knot.

“Seriously though… I’m… wow,” Shiro lifted a hand to Keith’s pussy, rubbing his thumb underneath the small bulge of Keith’s knot. The mood shifted again as Shiro’s gaze locked onto Keith’s cock and the knot under it. His eyes followed the movement of his thumb and forefinger as he rubbed the knot gently. 

Shiro’s irises were dark and his mouth was open just slightly as he leaned forward and gently pressed his lips against the swollen flesh. Keith gasped and closed his eyes, the gentleness of Shiro’s soft lips against the knot was intense. Shiro’s lips opened slightly and rubbed against the knot, moving up the small shaft of Keith’s dick before suctioning onto the head. 

Keith let out a soft moan, pulling his lower lip in between his teeth as Shiro’s mouth slowly moved down his dick. Keith wanted to buck up into Shiro’s face, he was moving so slow, but the anticipation made his knot _pulse,_ so he was patient. _Patience._

Shiro’s lips wrapped around Keith’s knot and his eyes shot open and he let out a long, broken sound. Shiro only hummed and started bobbing his head, ignoring the revelation Keith was having above him. 

Keith was losing his mind. Playing with his knot on his own was _nothing_ next to this. Shiro’s hot, wet mouth made such a tight suction around the knot it made Keith’s dick _throb._ Keith grabbed Shiro’s white hair in both hands and bucked his hips up against that welcoming mouth, fucking Shiro’s face roughly. 

Shiro’s eyes twinkled as they met Keith’s- he loved Keith going feral on him, using any part of him to get off. They’d realized this quickly into their relationship and Keith was more than happy to take advantage. Especially when Shiro’s lips were tightly suctioned to his throbbing knot and he could bob Shiro’s head on and off his cock like he never thought he’d be able to do pre-T.

“Oh god- Shiro, fuck, you’re so good at sucking my cock, _nng,”_ Keith tipped his head back and continued to thrust as he felt an orgasm build in his gut. “Fuck, I just wanna- _hhng-_ wanna knot you, wanna plug you up with my come- ffuck-” Keith’s orgasm hit him, cock throbbing as Shiro continued to suck, milking him of all he had until Keith had to push him off oversensitive. 

Shiro moved up Keith’s body, planting kisses as he went, “Fuck that was so hot baby-” Keith interrupted Shiro with a sloppy kiss, filthily licking the taste of himself out of Shiro’s mouth. Shiro stroked his thumb and forefinger along the length of Keith’s dick and Keith _growled._

In a split second Keith flipped Shiro, shoving him onto his back under him and tearing his slacks off. Shiro was chuckling but Keith ignored him. He was overcome with a sudden _need_ and he had to chase it, his knot was still thick and throbbing. It was different to the times on the ship when he’d played with himself, the knot would usually soften after he came, feeling slightly unsatisfied in a way he couldn't explain. 

But now he just- he had to _mount,_ he wanted- he _needed_ to come inside Shiro, fill him up with seed and plug it in there. Shiro bent his legs and opened them to fit Keith between his thick, muscled thighs. His cunt was wet when Keith quickly dipped two fingers in, spreading them apart to look inside that wet, ready cunt. 

Shiro’s pussy would get wet at the drop of a hat and _oh_ how Keith loved to exploit that, but right now all Keith could think about was how ready Shiro was to take his cock, take his knot and be bred up- “F-fuck, Shiro,” Keith pressed his hips against Shiro’s, struggling to find the right angle to press his cock against Shiro’s sopping wet hole.

They groaned in unison at the contact, but Keith was still spurred on by the need. Keith desperately thrust against Shiro’s wet cunt, Keith’s cock rubbing against the wet folds and up to Shiro’s own swollen dick. 

“Fuck, I wanna breed you up Shiro- fuck-” Shiro moaned brokenly at Keith’s words, gasping out a soft _“yes”_ as Keith’s hips rutted jerkily against his. “Wanna come inside your fertile cunt, fill you with my seed- _fuck…”_

Keith didn’t know where this was coming from- he could come, and he was barely able to nudge his cock against Shiro’s cunt, let alone _come inside him._ But the idea lit him up like gasoline on a flame. _“Fffuck,_ Shiro- wanna come inside you, make you take all my come- _nng-_ knot you up nice and good and make you hold my come inside you until you’re so f-fat with it, fuck…” 

Keith was rambling, but he couldn’t care less. Shiro’s cunt felt so soft and wet and _hot_ against his dick. The stimulation wasn’t the same around his knot as when Shiro’s mouth was on it, but the idea of plumping up Shiro with his seed more than made up for it.

Shiro was moaning with each rough thrust Keith laid on him, one hand was holding a leg up and the other was resting against Keith’s hip, fingers digging in deliciously. “Fuck, yes Keith, I want you to come in me, fuck-” Keith growled hearing his mate beg for it, if he was going to beg for it he was going to _get it._

Keith sat back and turned Shiro onto his side, mounting his thigh and continuing his punishing pace against Shiro’s cunt. At this angle he was able to better shove his cock and knot into Shiro’s wet pussy, hips rabbiting into that wet warmth. It felt so fucking good, so _right,_ his cock belonged in this cunt, belonged inside Shiro. 

“Your cunt was made to take me Shiro, made to take my seed, gonna make you take it- _fuck-”_

“Yes, please, fuck Keith- I was made for you please- _ah ahn-_ wanna carry your litter, wanna carry your kits-”

 _“FUCK-_ nng Shiro-” Keith’s hips stuttered as he came, squirting all over Shiro’s cunt and thighs. Keith thrust all through his orgasm, come squirting out of his cunt in hot gushes. He’d never squirted like this before, not without a serious pounding to his cunt. Shiro groaned and thrust against Keith as he was coated with his release, his own cunt spasming as his cock throbbed. His orgasm wasn’t as powerful as Keith’s, but watching him come like that more than made up for it.

Keith panted as he fell limply to Shiro’s side. The throbbing pressure of his knot had subsided and his head was slowly clearing, filled instead with that sated, post-sex haze he loved. Shiro nuzzled into Keith’s shoulder, wrapping his limbs around Keith’s sweaty body. Keith rolled onto his side to better accommodate snuggles, tucking his mate safely under his chin. 

Moments ago the room was filled with the sounds of skin slapping against skin, groans and panting, but now it was quiet, their breathing evening out as they cuddled. Shiro’s arms tightened around Keith, “I missed you baby. So fucking glad you’re home.”

Keith purred and nuzzled his face into Shiro’s soft hair, “Missed you so fucking much, it’s so good to be home.” Shiro’s body was so warm against his, despite the gross wetness now cooling and drying on their bodies, Keith was so comfortable and did _not want to move ever, no thanks._

“So that was all very hot, we gonna talk about it?” Shiro’s voice was light and playful and suddenly Keith was shy and a little embarrassed about his whole display.

“What, a guy can’t rub his knot against his bro’s cunt and talk about filling him up with seed? Bruh… come on…” 

“God, you’re so dumb, I love you.”

“I love you too.”

**Author's Note:**

> talk to me on twitter @hornycadetkeith


End file.
